1. Field of the Inventions
The invention relates to display devices and pertains to those in which ambient pressure is digitally displayed by electronic means.
2. Description of the Prior Art
Displace devices for showing ambient pressure are well known in industry as, for example, needle gauges which move in response to expansion or contraction of one or more pressure responsive springs. Similarly, devices are known in which the ambient pressure is displayed in response to the interaction between a linear variable differential transformer and a magnetic core mounted on the end of a Bourbon tube.
The latter deliver acceptable results, but linear variable differential transformers are expensive. Moreover, such devices require sophisticated electronics and stable power supplies for satisfactory operation.
Accordingly, one object of this invention is to achieve a device which incorporates the advantages of a Bourbon tube as a transducer, but without the expense of a linear variable differential transformer and its attendant need for complicated electronics and stable power sources.
Electronic gauges which transduce pressure from a Bourbon tube into an electronic output require substantial temperature stability. Specifically, output of electronic components is susceptable to temperature variations as are the physical dimensions of the Bourbon tube. If left uncompensated, temperature variations will produce erratic results.
Accordingly, another object of this invention is to minimize the influence of temperature variations on the components of in an electronic pressure gauge.